Microwave bonding of EVA and rubber items

ABSTRACT

Aspects of the present invention relate to systems and methods for customizing microwave energy distribution within a chamber to accommodate various load characteristics. Aspects of the present invention customized configurations of ports, deflectors, waveguides, conducting rods, and slots to shape and distribute energy.

BACKGROUND OF THE INVENTION

Shoes and similar items are often constructed from smaller parts madefrom rubber, foams, or other materials that require curing. Often, suchparts are irregularly shaped and/or composed of more than one type ofmaterial. Curing irregularly shaped parts and/or parts made fromdifferent types of materials through the application of heat can bechallenging, as attaining the desired temperature for different portionsof a part with differing thicknesses and/or made of different materialscan be difficult with traditional heating methods. Traditional heatingmethods for curing parts may use an oven, a heat press, or similarapproaches to heat a part for a curing process. In addition to thedifficulties of using ovens, heat presses, and the like to cure shoeparts due to energy distribution limitations, these methods also can beinefficient in their use of energy.

BRIEF SUMMARY OF THE INVENTION

The present invention generally relates to systems and methods forcustomizing a distribution of microwave energy within a chamber touniformly process a non-uniform workload, such as a shoe part.

Systems and methods in accordance with the present invention provide avariety of approaches to manipulate the distribution of microwave energywithin a chamber retaining a part to be cured. The chamber itself may beonly slightly larger than the part to be cured. The chamber may beconstructed of a conducting material that does not permit microwaveenergy to enter from the outside of the chamber to the inside of thechamber. Microwave entry points may be provided to permit microwaveenergy to enter the chamber at only selected locations relative to apart to be cured retained within the chamber. Such microwave entrypoints may be ports that connect to a waveguide that delivers microwaveenergy from a source to a chamber. The shape, size, and orientation ofsuch a port may be selected to attain a desired distribution ofmicrowave energy within the chamber, either alone or in combination withother features in accordance with the present invention. Microwave entrypoints may alternatively/additionally comprise openings in the chamberthat permit microwaves ambiently present around the chamber toselectively enter the chamber. Microwaves may be ambiently presentaround a chamber if, for example, the chamber has been placed into alarger microwave applicator chamber, such as a continuous feed microwaveoven.

Microwave heating has been used in food processing and other industriesto attain rapid and energy efficient heating of items. However,traditional systems and methods in microwave art do not providecustomized energy distribution necessary to uniformly process anon-uniform workload such as encountered by a shoe part to be cured.Traditional systems and methods are particularly disadvantageous whenworking with small chambers of a size required for a typical shoe part,as the traditional systems and methods applied to a small chamber mayfacilitate a blow torch effect. A blow torch effect is an effect of anintense amount of energy being concentrated on a specific portion of amaterial and the energy dissipating prior to reaching other portions ofthe material. Specifically, a blow torch effect may cause for a specificportion of material closest to a port to cure while leaving portionsfarther away from the port to remain uncured. The blow torch effect doesnot allow for materials to be uniformly cured.

Within a chamber in accordance with the present invention, a part to becured, which may be referred to as a “load” or a “workload,” may beretained within one or more dielectric materials. The dielectricmaterial may provide a cavity that retains the part to be cured and, ifdesired, to provide shape, textures, etc., to the part as it is heated.Multiple types of dielectrics may be used at different locations withina chamber. The use of different types of dielectric materials may alterthe distribution of the microwave energy, effectively refracting themicrowaves, but also may generate differing amounts of heat based uponthe interactions of the dielectric with the applied microwave energy.For example, a more “lossy” dielectric will heat more under appliedmicrowave energy than a less “lossy” dielectric. By selecting the type,amount, and orientation of different types of dielectrics within achamber, both the distribution of microwave energy and heat within thechamber may be selected.

Additional elements may be used to achieve a desired microwavedistribution within a chamber. For example, a conducting deflector mayprevent the over-curing of the portion of a part immediately alignedwith a microwave entry point. Other distribution plates may guidemicrowave energy to portions of the chamber where the energy is desiredand/or away from portions of the chamber where microwave energy is notdesired. By way of further example, a conducting rod extending throughthe wall of a chamber may transmit microwave energy from outside of thechamber into the chamber, and then may further distribute the microwaveenergy in a more desirable pattern within the chamber.

Further, because many curing processes require or benefit from theapplication of pressure, systems and methods in accordance with thepresent invention may apply pressure to the part to be cured within thechamber. Dielectrics may be selected that transmit applied pressure to apart within a cavity formed within the dielectric(s). The walls of achamber itself may be designed either to secure under a desired amountof pressure, for example when latched or otherwise secured into a closedposition, or to transmit pressure applied from an external source, suchas a conventional press.

Aspects of the present invention configure ports, deflectors,distribution plates, waveguides, and conducting rods to tune microwaveenergy based on characteristics of the non-uniform workload. In thisfashion, the distribution of microwave energy may be selected so as toachieve a desired amount of curing at all locations of a shoe part,which may require the application of the same or different amounts ofenergy to the shoe part. Systems and methods in accordance with thepresent invention may be used to cure parts intended for finishedproducts other than shoes, although parts for shoes are described inconjunction with some examples herein. Further, any type of materialrequiring or benefiting from curing or other processing by heating maybe processed using systems and/or methods in accordance with the presentinvention.

Aspects of the present invention may be particularly useful in curing ashoe sole. Generally, a shoe sole is shaped in a non-uniform manner. Forinstance, a heel portion of a shoe sole may have a shorter width than aball portion of a shoe sole. Further, as described further below, duringa curing process a volume of the shoe sole material may vary from theheel portion to the ball portion. Customizing the energy distributionthroughout a chamber allows for the shoe sole to be cured uniformlydespite the non-uniform shape and various other non-uniformcharacteristics.

Additional objects, advantages, and novel features of the invention willbe set forth in part in the description which follows, and in part willbecome apparent to those skilled in the art upon examination of thefollowing, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The present invention is described in detail below with reference to theattached drawing figures, wherein:

FIG. 1A is an exemplary microwave system used in various aspects of thepresent invention;

FIG. 1B is an exemplary microwave system used in various aspects of thepresent invention;

FIG. 1C is an exemplary microwave system used in various aspects of thepresent invention;

FIG. 1D is an exemplary microwave system used in various aspects of thepresent invention;

FIG. 2 is a schematic diagram energy distribution as described inrelation to various aspects of the present invention;

FIG. 3 is a schematic diagram energy distribution as described inrelation to various aspects of the present invention;

FIG. 4 is a schematic diagram energy distribution as described inrelation to various aspects of the present invention;

FIG. 5A is a schematic diagram of a chamber as used in various aspectsof the present invention;

FIG. 5B is a schematic diagram of a chamber comprising a load as used invarious aspects of the present invention;

FIG. 6A is a schematic diagram of a chamber including ports as used invarious aspects of the present invention;

FIG. 6B is a schematic diagram of a chamber including ports as used invarious aspects of the present invention;

FIG. 7A is a schematic diagram of a chamber including ports as used invarious aspects of the present invention;

FIG. 7B is a schematic diagram of a chamber including ports as used invarious aspects of the present invention;

FIG. 7C is a schematic diagram of a chamber including ports as used invarious aspects of the present invention;

FIG. 7D is a schematic diagram of a chamber including ports as used invarious aspects of the present invention;

FIG. 7E is a schematic diagram of a chamber including ports as used invarious aspects of the present invention;

FIG. 8 is a schematic diagram of a chamber including ports as used invarious aspects of the present invention;

FIG. 9 is a schematic diagram of a port orientation as used in variousaspects of the present invention;

FIG. 10A is a schematic diagram of energy distribution of port asdescribed in relation to various aspects of the present invention;

FIG. 10B is a schematic diagram of energy distribution of port asdescribed in relation to various aspects of the present invention;

FIG. 11A is a schematic diagram of a splitter as used in various aspectsof the present invention;

FIG. 11B is a schematic diagram of a splitter as used in various aspectsof the present invention;

FIG. 12A is a schematic diagram of a deflector as used in variousaspects of the present invention;

FIG. 12B is a perspective view of a deflector as used in various aspectsof the present invention;

FIG. 13A is a schematic diagram of energy distribution as described inrelation to various aspects of the present invention;

FIG. 13B is a schematic diagram of a chamber housing a load in relationto various aspects of the present invention;

FIG. 13C is a schematic diagram of a chamber housing a load in relationto various aspects of the present invention;

FIG. 14A is a schematic diagram of a slot as used in various aspects ofthe present invention;

FIG. 14B is a schematic diagram of a slot as used in various aspects ofthe present invention;

FIG. 15 is a schematic diagram of a slotted waveguide as used in variousaspects of the present invention;

FIG. 16 is a schematic diagram of a slotted waveguide as used in variousaspects of the present invention;

FIG. 17 is a schematic diagram of a slotted waveguide as used in variousaspects of the present invention;

FIG. 18A is a schematic diagram of a conducting rod as used in variousaspects of the present invention;

FIG. 18B is a schematic diagram of a conducting rod as used in variousaspects of the present invention;

FIG. 18C is a schematic diagram of a conducting rod as used in variousaspects of the present invention;

FIG. 19 is a schematic diagram of a chamber as used in various aspectsof the present invention;

FIG. 20 is a schematic diagram of a chamber as used in various aspectsof the present invention;

FIG. 21A is a perspective view of a top portion of a container as usedin various aspects of the present invention;

FIG. 21B is a perspective view of a bottom portion of a container asused in various aspects of the present invention;

FIG. 21C is a perspective view of a bottom portion of a container asused in various aspects of the present invention;

FIG. 21D is a perspective view of a top portion of a container as usedin various aspects of the present invention;

FIG. 21E is a perspective view of a top portion of a container as usedin various aspects of the present invention;

FIG. 21F is a perspective view of a top portion of a container as usedin various aspects of the present invention;

FIG. 21G is a perspective view of a top portion of a container as usedin various aspects of the present invention;

FIG. 22A is a schematic diagram of a chamber comprising a load as usedin various aspects of the present invention;

FIG. 22B is a schematic diagram of a chamber comprising a load as usedin various aspects of the present invention;

FIG. 23 is a schematic diagram of an EVA item and a rubber item inrelation to a aspects of the present invention;

FIG. 24 is a schematic diagram of wavelength in relation to aspects ofthe present invention; and

FIG. 25 is a flow of a method concerning a bonding of an EVA item to arubber item in relation to aspects of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Shoe construction in general, and the construction of athletic shoes inparticular, can present a challenge due to the diversity of materialsused in the construction of the shoes. Different types of materials mayrequire different processing techniques to form into individualcomponents, and further may be difficult to join together to create afully assembled shoe. One particular example of these challenges ofdiffering types of materials in a typical athletic shoe may be found inthe sole section of a shoe. The outsole of a shoe may typically beformed from a rubber or other durable material that may withstandcontact with the ground, floor, or other surface during wear. Themidsole of a typical shoe, on the other hand, may often be formed from adifferent material such as a foam type of material, like for example,ethylene-vinyl acetate (EVA) foam, sometimes to referred to as phylon.While other types of materials may be used to form an outsole and amidsole than these examples, in general the different purposes of anoutsole, to provide reliable contact with a surface, and a midsole, toprovide cushioning for the feet of a wearer, results in these differentsole components being constructed from different types of materials. Inexamples herein, a first material, such as rubber, and a secondmaterial, such as EVA foam, may be cured and/or joined. The term “EVA”will be used as shorthand for the wide range of materials, formulations,and blends of materials that may be used to form a shoe midsole, eventhough in some instances those materials may not comprise ethylene-vinylacetate in their entirety or even in part.

The use of different types of materials, such as rubbers and EVA, fordifferent portions of a sole assembly in an athletic shoe, requiresspecialized equipment and methodologies to prepare each of thosecomponents individually. Ultimately, after each component has beenprepared, an adhesive capable of bonding to both materials willtypically be used to engage them together. While both rubber and EVA, inthe present example, may typically be formed into a shoe part viaheating and/or the application of pressure, the amount of heat required,the length of time maintained at a given temperature, and the amount ofpressure required may differ markedly for an EVA material and a rubbermaterial. Complicating matters further, different regions of a midsoleand/or an outsole may benefit from a different amount, duration, heatand/or pressure provided to obtain optimal curing due to, for example,different thicknesses of the material at different places on the soleassembly of a shoe. By way of further example, the heal portion of ashoe intended for running may often be thicker when measured from top tobottom in an as-worn orientation than a portion of the midsoleassociated with the forefoot, making it desirable to apply more heat tothe heel portion of the midsole than to the forefoot of the midsoleduring curing. Unfortunately, such localized distribution of heat energyto a shoe part is not readily attainable with the conventional equipmentof an oven and/or heat press.

Even after different components of a shoe, such as a midsole and anoutsole have been prepared appropriately based upon the differingmaterials used, those two components may be still be assembled toproduce the final shoe product. This process typically involves the useof adhesives, which add cost and potential waste to the shoemanufacturing process, but which also provide a potential point offailure for the completed shoe. For example, an inadequate or irregularapplication of an adhesive to a midsole and an outsole may result in animproper joining of the two, leading to the outsole and midsole topartially or entirely separate after some amount of use. Obviously, sucha failure is undesirable on the part of both the manufacturer andultimate user of the shoe.

The present invention overcomes the challenges of preparing andultimately affixing components made from different materials in theassembly of a shoe through the customized distribution of microwaveenergy through a shoe part. The use of microwave energy to generate someor all of the heat required to properly cure a shoe part, for example apart made of rubber and/or EVA, may be difficult due to the irregulardistribution of microwave energy from most microwave applicators. Forexample, the experience of having a hot spot and/or a cold spot in afood dish being warmed in a microwave oven is one instance of these hotspots and cold spots. While hot spots and cold spots may be annoyingwhen warming food, they can be catastrophic in forming a shoe or shoepart. For example, an inadequate curing of a part may lead to the partsfailure, as may overcuring of the part. On the other hand, the intrinsicability of microwave energy to be distributed in a nonuniform fashionmay be useful for providing different amounts of heat to differentregions of a shoe part. Such a result may permit all regions of a shoepart to be cured to a desired degree, even if the dimensions andgeometry of the shoe part differs markedly in different regions.Further, systems and methods in accordance with the present inventionpermit the joining of different types of materials, in particular EVAmaterials and rubber materials, with reduced or even no need of anadhesive.

Systems in accordance with the present invention may retain a part orparts to be cured or otherwise processed within a cavity formed in atleast a first dielectric material. As explained further herein, multipletypes of dielectric materials may be used to alter the distribution ofmicrowave energy and/or the heat generated by the microwave energyinteracting with the dielectric itself. The dielectric or dielectricsmay be selected so as to be capable of transmitting energy to the shoepart or parts retained within the cavity. The dielectric with a shoepart or parts within the cavity may be placed within a chamber or othercontainer that may receive microwave energy. In one example, one or moreports attached to the walls of the chamber may deliver microwave energyat selected locations within the chamber. In another example inaccordance with the present invention, a waveguide may direct microwaveenergy around at least a portion of the perimeter of the chamber, withslots or other openings providing ports for microwave energy to exit thewaveguide and enter into the chamber. In yet a further example inaccordance with the present invention, a container having a plurality ofopenings permeable to microwave energy may be placed within a largermicrowave applicator chamber capable of sustaining standing microwaves,such that the plurality of openings selectively admit microwave energyinto the contents of the container, thereby achieving a desireddistribution of microwave energy across a shoe part or parts to beprocessed.

Various mechanisms may be used to direct microwave energy within achamber or container to achieve a desired distribution of energy over apart or parts to be processed. For example, the size and/or position ofa given port or slot may be based upon the desired distribution ofmicrowave energy relative to a shoe part contained within a chamber. Afurther possibility for manipulating the distribution of microwaveenergy within a chamber or container is the use of deflectors and/ordistribution plates. As explained herein, a relatively small chamber,i.e. one that is only a few multiples of a wavelength, may experience aneffective ‘blow torch’ of microwave energy immediately after themicrowave energy passes through a port and into a chamber. The primaryand secondary lobes of microwave radiation entering a chamber through aport may overcure a part. In a small chamber, a radiation pattern, suchas the envelopes of primary and secondary energy lobes, may occupy asubstantial portion, such as at least ten percent or more, of thechamber. The primary lobes may form the ‘blow torch’ and comprise anintense amount of energy. In accordance with the present invention, thisintense energy may be deflected and distributed uniformly using aconducting deflector plate oriented between the port or other openingdelivering the microwave energy to the chamber and the part or parts tobe processed. A distribution plate may similarly comprise a conductivematerial oriented within a chamber or container to distribute microwaveenergy along and/or within the chamber. Generally speaking, a deflectormay be thought of as a conducting material oriented between a port,opening, or other microwave energy application point and the part orparts to be processed, while a distribution plate may be thought of as aconductive material oriented away from the path between a port, opening,or other microwave energy source and the part or parts to be processed.Yet further elements that may be useful in directing energy in a desireddistribution over a shoe part or parts are described herein, such asconducting rods that may be paired with slots, ports, or other openings,arrangements of slots or other openings to selectively permit theentrance of standing microwaves and the like.

Microwave energy applied to one or more items using systems and/ormethods in accordance with the present invention may be used to performa variety of functions. For example, EVA material may be melted, foamed,and/or bonded in accordance with the present invention.

Further, examples of systems in accordance with the present inventionmay provide or permit the application of pressure to a part or parts tobe processed. Such pressure may come from a conventional press that mayexert pressure on opposing sides of a chamber, the construction of thechamber itself, or any other source.

Some examples of the present invention described herein generally relateto systems and methods for customizing a distribution of microwaveenergy within a chamber of a compact microwave press (CMP) to uniformlyprocess a non-uniform workload. The nonuniform workload may comprise oneor more materials. Aspects of the present invention configure ports,deflectors, distribution plates, waveguides, and conducting rods to tunemicrowave energy based on characteristics of the non-uniform workload,such as components of a shoe.

Aspects of the present invention may be particularly useful in curing ashoe sole. As described in the present invention, a CMP may be used tocure a shoe sole material. Shoe sole material may comprise midsolematerial and/or outsole material. Midsole material may comprise any typeof cushioning and/or ornamental material for a shoe midsole. EVA foammay be referenced in examples herein as a midsole material, but othermaterials may be cured or otherwise processed in accordance with thepresent invention. Outsole material may comprise any material thatcontacts the floor, ground, or other surface when a shoe is worn. Rubberis referenced in examples herein as an outsole material, but othermaterials may be cured or otherwise processed in accordance with thepresent invention. FIG. 1A shows system 100 that may be utilized withaspects of the present invention in curing a shoe sole material. FIG. 1Ashows a microwave filled chamber 110, a workload 111, a thermal heatingcomponent 112, a pressure application component 113, a microwavegenerator 114, a primary transmission line component 115, a secondarytransmission line component 116, a tertiary transmission line component117, and a computing device 118. Aspects of the present invention mayutilize any combination of the components of system 100, additionalcomponents, and/or fewer components. The microwave chamber 110 may befilled with dielectric containing workload 111 within a cavity formed inthe dielectric. Dielectric may comprise multiple physical portions ofmaterial that may be opened or separated to permit the insertion of aworkload into the cavity. The microwave chamber 110 is connected to themicrowave generator 114 by the primary transmission line component 115,secondary transmission line component 116, and tertiary transmissionline component 117. The microwave generator 114 may optionally becoupled to the computing device 118. The computing device 118 may becoupled to the thermal component 112 and/or pressure applicationcomponent 113. Computing device 118 may adjust the application ofmicrowave energy from microwave generator 114 and/or the amount ofpressure applied by pressure application component 113 based uponparameters such as the time elapsed within a curing cycle and/or thetemperature measured by a thermal component 112.

The energy inside of the chamber 110 is coupled from the microwavegenerator 114 through the transmission line components. The selection,configuration, and/or arrangement of transmission line components enabletuning of the microwave energy delivered and enable a high degree ofcustomization of energy distribution within the chamber 110. The primarytransmission line components 115 connect the generator and the chamber.The secondary transmission line components 116 are used at an interfacebetween the primary transmission line 115 and the chamber 110. Thetertiary transmission line components 117 are used inside the chamber110 to modulate the energy around the workload. The tertiarytransmission line components 117 may be used to focus or to defocusenergy into the workload or a portion of the workload. Primarytransmission line component 115 may comprise a waveguide (in the presentexample) or the open space of an applicator chamber (described insubsequent examples), or any other mechanism that delivers microwaveenergy to a chamber such as chamber 110 in the present example.Secondary transmission line component 116 may comprise an entry pointfor microwave energy to enter the chamber. Secondary transmission linecomponent 116 may comprise a port connected to a waveguide (as in thepresent example), a slot or other structure joining a chamber to awaveguide (as described in examples below), openings in the chamber thatpermit the entry of microwave energy from the ambient space around thechamber (as also described in examples below), or any other structurethat permits microwave energy to enter the chamber 110. Tertiarytransmission line component 117 may comprise any additional componentthat alters the distribution of microwave energy within the chamber 110.Tertiary transmission line components 117 may comprise conductingdeflector plates, conducting distribution plates, conducting rods, andthe like, some examples of which are described further below. Further,the type and/or configuration of dielectric material may vary within thechamber 110, further altering the distribution of microwave energywithin the chamber 110. A system in accordance with the presentinvention may omit tertiary transmission line components 117 if primary115 and secondary 116 transmission line components achieve a desireddistribution of microwave energy within a chamber 110.

FIGS. 1B, 1C, and 1D show variations of a chamber 110 assembly that maybe used in aspects of the present invention. FIG. 1B shows an exemplarychamber 110 housing a load 111 and a dielectric 120, where the chamber110 is in between a first press component 130 and a second presscomponent 135. FIG. 1C shows an exemplary chamber 110 housing a load 111and a dielectric 120. The exemplary chamber 110 comprises a top portion135 and a bottom portion 130. The load 111 is located in the bottomportion 130 in this example. Connecting the top portion 135 to thebottom portion 130 in this example is a hinge 140. Hinge 140 is attachedto the top portion 135 and the bottom portion 130 and comprises jointsthat may facilitate the chamber 110 in moving between an open position,with the top portion 135 raised and a closed position, with the topportion 135 lowered onto the bottom portion 130. A latch 145 may beattached to the top portion 135 and bottom portion 130 to allow the topportion 135 to remain lowered and connected to the bottom portion 130.FIG. 1D shows an exemplary chamber 110 housing a dielectric 120 andcomprising a top portion 135 and a bottom portion 130, where the bottomportion houses a load 111. Connecting the top portion 135 to the bottomportion 130 in this example is a retainer 140. The retainer 140comprises latching components 141, 142, 143, 144, 145, 146, 147, 148,149, and 150 that facilitate a connection between the top portion 135and the lower portion 130. Latching components 141-150 may comprisescrews, clamps or any other items that facilitate a connection betweentwo components.

Generally, curing of an EVA or similar material comprises across-linking of a polymer chain with another polymer chain and occurswhen an EVA material is heated. A typical shoe sole is shaped in anon-uniform manner as the heel portion of the shoe sole may have ashorter width and taller height than the ball portion of the shoe sole.Curing a shoe sole may involve placing an EVA material inside a shoemold where the original size of the EVA material is substantially lessthan the size of the shoe mold. During the curing process the size ofthe EVA material may expand to become a size similar to that of the shoemold. Additionally, the volume and mass of the EVA material may changethroughout the curing process. Curing a shoe sole may also involveplacing an EVA material inside a shoe mold where the original size ofthe EVA material is similar to the size of the shoe mold. During thecuring process, the volume, mass, and size of the EVA material insidethe shoe mold may change. Because the volume, mass, and size of EVAmaterial within a shoe mold may change throughout the curing process,various portions of the EVA material may require differing amounts ofenergy. For instance, EVA material associated with the heel portion of ashoe sole may require less energy than EVA material associated with theball portion of a shoe sole.

Explained further, an EVA material that is to be cured may havecross-linking agents and blowing agents. If the EVA material undergoespoor curing prior to the activation of the blowing agent, then theinnate strength of the under-cured (low cross-link density) portions ofthe EVA material will not adequately counteract the expansion caused bythe blowing agent. The under-cured areas will expand more than the curedareas (high cross-link density). The catalyst and the blowing agentshave thermal windows of activation that are sequential to one another.Any thermal non-uniformity established in the cross-linking inmanifested as exaggerated bloating caused post-activation of the blowingagent. If the EVA material undergoes poor curing with low cross-linkingdensity prior to the activation of the blowing agent, then the innatestrength of the EVA material in the under-cured portions will notadequately counteract the expansion caused by the blowing agent causingthe under-cured areas to expand more than the cured areas of highcross-linking density.

FIG. 2 shows an example of a material 204 that is non-uniformly cured.In the example of FIG. 2, material 204 comprises a rectangular preformedEVA material, rather than an even more challenging shape. FIG. 2 shows awaveguide 201 with a port 209 providing energy, shown as a primaryenergy lobe 202 and secondary energy lobes 211, 212, 213, 214, 215, and216, into a chamber 203 that houses a material 204. A shaded area 220 ofmaterial 204 has a wider width than the surrounding areas 222 and 224 ofmaterial 204. The variation of widths in material 204 is due tonon-uniform curing. FIG. 3 also provides of an example of material thatis non-uniformly cured. FIG. 3 shows a waveguide 301 with a port 399providing energy, shown as a primary energy lobe 302 and secondaryenergy lobes 311, 312, 313, 314, 315, and 316, into chamber 303 thathouses material 304. A shaded area 320 of material 304 has a narrowerwidth than the surrounding areas 322 and 324. The variation of widths inmaterial 304 is due to non-uniform curing.

Characteristics of a load may affect the uniformity of a load during acuring process. Characteristics of a load may be a silhouette, a volume,a mass, a length, width, a height, a type of material, a location of theload in relation to a port, a location of the load in relation to adeflector, a location of the load in relation to distribution plate, alocation of the load in relation to a portion of a chamber, a locationof the load in relation to an conducting rod, and a location of the loadin relation to a waveguide. One portion of a load may require an amountof energy different from another portion due to the characteristics of aload being non-uniform. For instance, a heel portion of a shoe sole mayhave a larger mass than a ball portion of a shoe sole.

Aspects of the present invention may comprise processing a loadcomprised or rubber and/or compositions of ethylene vinyl acetate, suchas EVA. As will be described further below, a load may be placed withina cavity formed in at least a first dielectric material within achamber. The chamber may be comprised of materials that allow microwaveenergy to effectively heat EVA and rubber. The chamber may beconstructed of materials that may not completely absorb or completelyreflect microwave energy. Further, the chamber may be constructed ofdielectric materials that are optimized for thermal conductivity toenable uniform and rapid temperature equilibration when heated toprepare for a curing process. The dielectric materials may also beoptimized for thermal conductivity to enable uniform and rapidtemperature equilibration when cooled to enable demolding of a part withminimal distortion and during a process of curing. The materials of thechamber may structurally withstand temperatures and pressures up to 300degrees Celsius and 2000 psi internal pressure. In certain aspects ofthe present invention, the materials may need to withstand only 150degree Celsius temperature and less than 500 psi internal pressure.

Examples of dielectric materials that may fill a chamber and provide acavity to retain a load are Liquid Silicone Rubber (LSR), neat Teflon,glass-filled Teflon, (neat Teflon and glass-filled Teflon may bereferred to herein as ‘PTFE’), and epoxy, but any type of dielectricmaterial may be used in accordance with the present invention. In LSRthe relative permittivity (relative to vacuum) approaches that of EVAand the dielectric loss factor with respect to temperature is much lowerthan EVA as it approaches a process temperature. This allows energy topropagate uniformly through the combination of mold and/or partmaterials and preferably heat the EVA as it may have a higher lossfactor. In aspects of the present invention, to transfer heat in anefficient manner the LSR or other dielectric may be pre-heated beforethe process of curing in order to conduct heat to an EVA item, which mayallow the EVA item to result in a surface volume that is similar to theinternal volume.

The relative permittivity PTFE is lower than the relative permittivityof EVA in the process temperature. PTFE has a very low dielectric lossfactor with respect to temperature and will only heat up slightly in amicrowave energy field. These properties allow uniform microwave energypropagation. In aspects of the present invention, PTFE is heated up to aprocess temperature to provide enough heat at the surface to obtainuniform reactivity at the surface and within the volume of the EVA. Thethermal conductivity of PTFE is also low, so heat does not transfer veryeffectively. To be effective as part of the overall molding process,PTFE may have a higher thermal conductivity than the load (viacompounding) and be as thin as possible to minimize mass and distancefor heat to travel.

Epoxy heats up more quickly in response to microwave energy than EVA.Aspects of the present invention balance the heat generated in EVA andthe cavity comprising epoxy in order to balance out interfacial heatingwith center part heating. This is accomplished by changing the thicknessof the epoxy material comprising the cavity at a loss factor close tothat of EVA. The dielectric constant of the epoxy should be as close tothe dielectric constant of EVA as possible to allow uniform propagationof microwaves through both materials.

For at least these reasons, it is highly desirable to have customizableenergy distribution inside a chamber as the curing of material isrelated to the energy distribution. Aspects of the present inventionallow for energy distributions within a chamber to be customized inorder to facilitate uniform curing a non-uniform load based on variouscharacteristics of the material.

In order to provide an easy to understand description of the aspects ofthe present invention, this description is divided into a discussion ofthree key systems, those systems are: (1) multiport launch, (2) modifiedslotted waveguide, and (3) a cage. Although the three key systems may bediscussed individually, characteristics, components and features of eachsystem may be interchangeably used and/or combined with one another.

Multiport Launch

One example of a system in accordance with the present invention may bereferred to as a multiport launch system. A multiport launch systemfacilitates a shaping of energy distribution within a chamber utilizinga combination and customized configuration of launch ports anddeflectors. The combination and customization of launch ports anddeflectors are based on characteristics of the load, such as length,width, and density. Further, aspects of the multiport launch systemcomprise a use of conducting rods, waveguides, and distribution plates,which may also be configured and customized based on characteristics ofthe load. Aspects of the present invention may be particularlyapplicable when an antenna irradiation pattern occupies a substantialportion of a chamber and when at least a portion of a load intersectsthe irradiation pattern.

An example of a launch port and deflector being configured to customizeand shape energy distribution is shown in FIG. 4. FIG. 4 shows awaveguide 401 with a port 499, providing energy in the form of a primaryenergy lobe 402 and secondary energy lobes 411, 412, 413, 414, 415, and416, into chamber 403 housing a load 404 and deflector 430. Instead ofthe energy lobes 402 and 411-416 meeting the load 404 directly, theenergy lobes first meet the deflector 430 as the deflector is positionedbetween the waveguide 401 and the load 404. The deflector 430 may causethe energy lobes 402 and 411-416 to travel around the deflector 430,thus customizing the energy distribution within the chamber.

As indicated above, a multiport launch system utilizes combinations andconfigurations of launch ports, deflectors, distribution plates,conducting rods, and waveguides to customize energy distribution basedon characteristics of a load. Each of the launch ports, deflectors,distribution plates, conducting rods, and waveguides will be describedindividually and in combination with one another below. However, thecombinations and features of launch ports, deflectors, distributionplates, conducting rods, and waveguides are not limited to theseexamples.

A chamber associated with the multiport launch may be small relative tothe wavelengths of microwave energy applied. In certain aspects, achamber may comprise a length of 10 inches, a width of 4 to 6 inches,and a height of 2 inches. However, the measurements of a chamber mayvary based on a size of a shoe sole construction. In some aspects, achamber may be configured to allow up to 2 to 3 wavelengths in distancebetween a load and a surface of the chamber, but the load may bepositioned only a small fraction of a wavelength from the surface of thechamber as well. The chamber may be of various shapes, includingrectangular or square. A workload associated with the multiport launchremains stationary inside the chamber, but also may be formed from oneor more curved surfaces. In some aspects, the load may reside within adistance within 1 to 3 wavelengths from a launch port. A chamber mayhave a top portion, bottom portion and one or several side portions. Tomore easily describe aspects of the present invention, an exemplarychamber 500 is provided in FIG. 5A that has a top portion 502, bottomportion 504, and four side portions 501, 503, 504, and 506, where eachof side portion 505 and 506 have a length longer than that of sideportions 501 and 505.

A chamber associated with aspects of the present invention may beconstructed of a conducting material, such as steel, copper, aluminumand/or titanium. One or more dielectric materials may be containedwithin a chamber. The one or more dielectric materials in a chamber mayhave a cavity configured to retain a load, such as a molded part, orother materials associated with a shoe sole construction. In someaspects, for instance aspects concerning a load comprising EVA in a foamform, the dielectric constant of the dielectric materials within thechamber may be greater than or equal to the dielectric constant of theload. In other aspects, the dielectric constant of the dielectricmaterials within the chamber and may be less than or equal to thedielectric constant of the load contained within the cavity in order toeffectively transfer heat to the load.

FIG. 5B provides a layered illustration of chamber 500 with a topportion 502, a bottom portion 504, and side portions 501, 503, 504, and506. FIG. 5B also shows a load 550 which may be placed within a cavitybetween a top portion of a dielectric material 520 and a bottom portionof a dielectric material 530. A top portion 525 of the cavity may extendinto the top portion of the dielectric material 520, and a bottomportion 535 of the cavity may extend into the bottom portion of thedielectric material 530.

Aspects of the present invention comprise a variety of numbers,placements, and configurations of launch ports to customize energydistribution. In some aspects, a multiport launch system may have onlyone launch port. In other aspects, a multiport launch system may havetwo, three, four, or more launch ports. Launch ports may be placed on atop portion, bottom portion, or any side portions of a chamber. Forinstance, a launch port may be placed at top portion 502 of chamber 500.

In aspects that have more than one launch port, the launch ports may beplaced in specific configurations in relation to one another in order tocustomize energy distribution. In one aspect, as shown in FIG. 6A,chamber 500 has a load 530 with port 610 located at side portion 505 andport 620 located at side portion 501.

FIGS. 6B and 7A-7E provide schematic illustrations of chamber configureswith various numbers of ports. FIG. 6B shows a schematic illustration ofa chamber 500 housing a load 530 with port 610 located at side portion501 and port 620 located at side portion 505. In another aspect, asshown in FIG. 7A, chamber 500 has a load 530 with ports 720 and 730located at side 505, ports 750 and 760 located at side 50, ports 710 and770 at side 501, and ports 740 and 780 at side 503. Additionally, port770 is located at a corner of side portion 501 and 505 and port 780 islocated at a corner of side portion 503 and 506.

FIG. 7B shows a chamber 500 has a load 530 with ports 720 and 730located at side portion 505, ports 750 and 760 located at side portion506, ports 710 and 770 located at side portion 501, and ports 740 and780 located at side portion 503. As shown in FIG. 7B, port 720 may bestaggered a length of 799 from port 760, and port 730 may be staggered alength of 798 from port 750. Lengths 798 and 799 may be measured from acenter of ports 720, 730, 750 and 760. Lengths 798 and 799 may varybetween ¼ to ½ wavelength. Lengths 798 and 799 may be large enough toprevent plumes of microwave radiation from opposing sides to overlap. Bystaggering ports between ¼ and ½ wavelength, a complimentary radiationpattern, standing waves may be established within the chamber providinguniform energy distribution. For clarity purposes, a microwave 2400 isillustrated in FIG. 24. Microwave 2400 may have a wavelength betweenpoints 2401 between lines 2410 and 2420. Further, an effectivestaggering of ports may be obtained by switching ports between an openposition and a closed position such that ports may not have tophysically be staggered in order to obtain the effect of a complimentaryradiation pattern. For instance, for a first port and a second portlocated across from one another, the first port may be closed while thesecond port may be open. In this instance, multiples of the first andsecond port configuration may be provided within a chamber to establisha standing wave pattern. Ports may be associated with switches or acomputing system in order to switch a port from a closed position or anopen position. Additionally, metallic tape may be used to close a port.

FIG. 7C illustrates a chamber 500 comprising ports a varying heights andlocations on side portions 506 and 505. Port 730 may be located at adistance 704 from the bottom portion 504, a distance 703 from topportion 502, a distance 740 from side portion 501 and a distance 742from side portion 505. Port 720 may be located at a distance 702 fromthe bottom portion 504, a distance 701 from top portion 502, a distance741 from side portion 501 and a distance 743 from side portion 505.Generally, ports may be located at any height and/or location within achamber.

FIG. 7D illustrates a chamber 500 comprising staggered ports and a portlocated in a corner. Port 730 may be staggered a distance of 798 fromport 750. The distance 798 being between lines 790 and 791 where lines790 and 791 are illustrative of a center of port 730 and port 750,respectively. Port 720 may be staggered a distance of 799 from port 760.The distance 799 being between lines 792 and 793 where lines 792 and 793are illustrative of a center of port 720 and 760 respectively. Distances798 and 799 may be varied between ¼ to ½ wavelength. As described above,by staggering ports between ¼ and ½ wavelength, a complimentaryradiation pattern, standing waves may be established within the chamberproviding uniform energy distribution.

Additionally, ports may be located in any corner of a chamber. Port 770of FIG. 7D is shown as being located in a corner, the corner comprisingintersecting planes of side portion 501 and side portion 505. In someaspects, a first port may be located in a corner comprising intersectingplanes of side portions 501 and 506 near top portion 502 while a secondport may be located in a corner comprising intersecting places of sideportion 505 and 503 near the bottom portion 504 and/or near the topportion 502.

In some aspects, a plane of an internal wall of a waveguide may bematched to a plane of a chamber allowing the chamber to seeminglyseamlessly extend from the waveguide as shown in FIG. 7E. FIG. 7E showsa waveguide 701, a port 702 and a chamber 500. A plane of an internalwall of waveguide 701, illustrated at 710 is matched to the plane 720 ofchamber 500 minimizing a mismatch between a waveguide and a chamber.

With continued reference to FIG. 8 for exemplary purposes, various portsmay provide varying amounts of power or energy per unit of time fromdifferent ports. For instance, port 720 may provide a different amountof energy than port 730. Additionally, port 720 may provide energy for adifferent amount of time than port 760. In some aspects, port 720 mayprovide a higher amount of energy for a shorter amount of time than port760. In other aspects, port 720 may provide a higher amount of energyfor a longer amount of time than port 760. In some aspects, a computersystem, such as computer system 118 of FIG. 1A, may be configured tocontrol and program an amount of energy provided at each port.

A port may be configured at a specific entrance angle and at a specificorientation angle. Referring to FIG. 9, side portion 501 is shown withport 710. In order to provide a description of various entrance anglesand orientation angles, an x-axis 510, y-axis 511, and z-axis 512 withangles 520 and 521 in relation to port 720. Entrance angle 520 may varyfrom 30 degrees and 120 degrees. Orientation angle may vary from 30degrees to 120 degrees. The orientation and entrance angle may change adirection of energy lobes entering a chamber, allowing for energydistribution.

FIG. 10A shows a waveguide 1001 with a port 1099 and energy lobescomprising a primary energy lobe 1002 and secondary energy lobes 1010,1011, 1012, 1013, 1014, and 1015. The orientation of the waveguide thatcouples microwave energy into the chamber influences both the directirradiation heating as well as the modal pattern heating. As shown incomparison of FIG. 10A to 10B, the energy lobes 1010 to 1015 are turned90 degrees when waveguide 1001 is twisted by 90 degrees to provideenergy lobes 1020, 1022, and 1024. Given an energy lobe pattern, whichdepends on the waveguide geometry and the operating frequency, energylobes may intersect a load in specific positions and drive the heatingpreferentially in those positions.

Energy distribution may be customized using a splitter to split anamount of energy received at a port. FIG. 11A shows a splitter 1100which may be used to distribute energy in two or more locations within achamber. For instance, as shown in FIG. 11B, ports 1110 and 1120 areprovided into chamber 500 such as ports 1110 and 1120 may be attached toone splitter 1100, splitter 1100.

Aspects of the present invention have deflectors positioned within achamber, such as chamber 500. A deflector is a component placed within achamber to shape energy lobes and customize energy distribution.Generally, a deflector reflects microwave energy. A deflector may beformed of a conducting material, may have various shapes, and may beformed from continuous or non-continuous (for example, perforated orslotted) material. A deflector may be of various materials such a steel,copper, and titanium. FIG. 12A shows an exemplary deflector 1201 with anarc 1210. The arc 1210 of deflector 1200 may range from 0 to 180degrees. FIG. 12 b provides a perspective view of deflector 1200 showinga height of 1220, a length of 1222, and a width of 1224. The height1220, may range from ⅛ to ¾ a height of a corresponding chamber. Thelength, 1222, may range from ⅛ to ¾ a length of a corresponding chamber,and width 1224 may range from, may range from ⅛ to ¾ a length of acorresponding chamber.

A deflector may be placed at any location within the chamber.Additionally, a deflector may be placed at an angle ranging from 0 to 90degrees from the plane of the bottom portion 504, top portion 502, orany side portions 501, 503, 505, and 506 of the chamber 500. As shownpreviously in FIG. 4, a deflector 430 may be placed between a load 404and a port 401. In some aspects, deflector 430 is placed within onewavelength of port 401. Generally, the most intense and highest energylobes are located within one to two wavelength of the port. The areanearest to the port with the most intense energy may be referred to asthe nearfield and is often considered to be within two wavelengths ofthe port. Placing a deflector within one wavelength of a port allows thestrongest lobes of energy to be directed around the deflector.Additionally, placing the deflector within one wave length of the portpositions the deflector between the workload and the port preventing ablow torch effect from happening to the workload.

In aspects that have more than one port, a deflector may be placedbetween each port and the load. Additionally, deflectors may be placedwith a specified distance from a load. As shown in FIG. 13A, a chamber1300 may be attached a waveguide 1310 with a port 1399 and house a load1330 and deflector 1320, and distribution plates 1321 and 1322.Deflector 1320 is located between port 1310 and load 1330. Distributionplates 1321 and 1322 are placed at a specified distance 1350 and 1351,respectively, from the load 1330 and not between the port 1310 and theload 1330. Additionally, load 1330 and deflector 1320 may be separatedby distance 1352, and port 1310 and deflector 1320 may be separated by adistance 1353. Distribution plate 1322 and a side portion 1305 may beseparated by a distance 1355. Load 1330 and side portion 1356 may beseparated by a distance 1356. Distribution plate 1321 and side portion1307 may be separated by a distance 1354. A specified distance, such asspecified distances 1350 to 1356, may be between zero and ½ a width or alength of chamber 1300. FIG. 13A shows an energy distribution 1340 and1345 shaped and customized by deflectors 1320, 1321, and 1322. FIG. 13Bshows a deflector 1320 and distribution plate 1321 next to a load 1330.Deflector 1320 comprises a length 1360 and a height 1362. Distributionplate may have a length 1364 and a height 1366. The load 1330 may have alength 1368 and a height 1370. The lengths, widths, and/or heights 1360,1362, 1364, 1366, 1368 and 1370 may be between zero and ¾ a width or alength of chamber 1300. In some aspects, heights 1362 of deflector 1320and 1366 of distribution plate 1330 may be greater than or equal toheight 1370 of load 1330. Additionally, in some aspects, lengths 1360 ofdeflector 1320 and 1364 of distribution plate 1330 may be greater thanor equal to length 1368 of load 1330. Further, height 1362 of deflector1320 may be different from or equal to height 1366 of distribution plate1330 and length 1360 of deflector 1320 may be different from or equal tolength 1364 of distribution plate 1330.

FIG. 13C shows a chamber 1300 comprising ports 1310 and 1311, deflectors1380 and 1381, a distribution plate 1382, and a load 1330. Forillustration purposes dotted lines 1390 and 1391 are shown between port1311 and load 1330. Line 1390 runs from port 1311 through the load 1330.Line 1391 runs from port 1310 through the load 1330. Deflector 1380 islocated on line 1391 and between port 1310 and load 1330. By deflector1380 being located on line 1391 between the port 1310 and 1330, thedeflector prevents the load 1330 from directly receiving microwaveenergy directly from the port 1310. Similarly, by deflector 1381 beingon line 1390 and between port 1311 and load 1330, deflector 1381prevents the load 1330 from directly receiving microwave energy fromport 1311. As shown, distribution plate 1382 is not located on either oflines 1390 or 1391. Distribution plate 1382 allows for energy within thechamber 1300 to be shaped around the load 1330.

Aspects of the present invention have distribution plates. Adistribution plate facilitates a flow of energy. Using FIG. 5 as areference, a distribution plate may be placed on the bottom portion 504,top portion 502, or side portions 501, 503, 505, or 506 of chamber 500.Additionally, a distribution plate may be placed at an angle rangingfrom 0 to 90 degrees from the plane of the bottom portion 504, topportion 502, or any side portions 501, 503, 505, and 506 of the chamber500. In relation to a load, a distribution plate may be placed above andbelow a load to provide customized energy distribution.

Energy transfer to a load may be performed using materials that aredielectric materials and composites made of dielectric materials.Dielectric materials are electrical insulates and do not have freeelectron conductivity. Dielectric materials inside the multiport chambermay be relatively microwave transparent. The temperatures and thepressures required by the curing process are transferred to the workloadusing dielectric materials. Dielectric materials are a class ofmaterials that have relatively poor thermal conductivity. The poorthermal conductivity of dielectric materials allow for the transfer ofpressure to the workload. It is advantageous for the chamber to be assmall as possible in order to minimize the total amount of dielectricmaterial to be heated and cooled.

In aspects of the invention, to obtain uniform volumetric heating of aload, the materials immediately surrounding the load may also heat inresponse to the applied microwave energy to further heat the load viaconduction. The dielectric properties and the mass of the load willdictate at what temperature surrounding materials should start at andshould allow more uniform volumetric temperature rise in a uniformfield. The surrounding material can be inheritantly lossy, such as ETFE,or can be a relatively low loss base polymer compounded with additivesto achieve the correct properties, such as silicones (across entiremodulus range), polyimides, LCP, fluorocarbon based materials,compounded with lossy solid materials such as high temperature hydrates(Mg(OH)2, Al(OH)3, or SiC, etc. Any structural material not in contactwith a load may be low loss and low dielectric constant and high thermalconductivity to allow uniform propagation and heat transfer.

Slotted Waveguide

Systems in accordance with the present invention may use a slottedwaveguide to deliver microwave energy into a chamber. Aspects of aslotted waveguide facilitate a customization of energy distribution toaccommodate various load characteristics using multiple slots wheremicrowave energy is picked up and transmitted into a chamber using slotswithin the slotted waveguide. In effect, the multiple slots becomemultiple ports, distributing energy into a chamber. In some aspects, themultiple slots surround a load and transmit uniformly over time. Anyvariable frequency microwave generator may be used in systems inaccordance with the present invention. For example, a variable frequencymicrowave (VFM) generator producing 4096 sequential frequencies all withdifferent standing wave patterns in the slotted waveguide may be used.In some aspects, the microwave frequency may range from 5850 MHz to 6650MHz. Each pickup position of a slot and the geometry of the slot in suchan example will affect the microwave transmission of other slots. Tuningof a port and the slotted waveguide configurations allows for uniformtemperature rise within the chamber to be achieved, or other temperaturedistributions as desired or needed for a particular load. All ports mayradiate differently, but over time an average energy distribution may beachieved. The nearfield ‘blowtorch’ effect is mitigated by distributionof the same amount of energy over several points, and/or several slots.In some aspects, none of the slots have enough energy to cause a‘blowtorch’ effect in a load. If needed or desired, however, deflectors,distribution plates, and the like, in accordance with the presentinvention may be positioned to mitigate any blowtorch effect and/or tootherwise distribute microwave energy in a desired pattern.Additionally, in some aspects, energy coming into the cavity propagatesfrom a conducting rod and has fundamentally different lobe patterns, allat intensity and temperature levels lower than the intensity andtemperature levels of the energy in the nearfield of the port.

FIG. 14A shows a slot 1410 that may be provided in a slotted waveguidesystem in accordance with the present invention. The length 1420 of slot1410 may vary from, for example, approximately ⅛ a wavelength to 1wavelength. The height 1425 of slot 1410 may vary from, for example, ⅛wavelength to 1 wavelength. FIG. 14B shows a modified slot 1450 that maybe used in a modified slotted waveguide system in accordance with thepresent invention. Modified slot 1450 have a height and width similar toslot 1410. Further, modified slot 1450 may have regions 1460, 1462, and1464 where the width of regions 1462 and 1464 are greater than the widthof region 1460 forming a “dogbone” shape that may alter microwave energydistribution patterns and, as further described below, may permit one ormore conducting rods to be retained by modified slot 1450.

FIG. 15 shows an exemplary slotted waveguide 1500 has slots 1510, 1511,1512, and 1513. Slots 1510, 1511, 1512, and 1513 are similar to slot1410 and are distributed above and below a median 1540. The distancebetween each slot 1530 may vary from, for example, about ⅛ a wavelengthto 1 wavelength. The length of a slot, such as slot 1512, may also varyfrom, for example, ⅛ a wavelength to 1 wavelength. Additionally, thedistance 1534 between the end of a waveguide 1520 and an initial slot,such as slot 1513, may vary, for example, between about ⅛ wavelength and1 wavelength and multiples thereof. In some aspects, the distance 1534is a quarter wavelength from the end of the waveguide 1520.

FIG. 16 shows an exemplary slotted waveguide 1600 with slots 1610, 1611,1612, and 1613. Slots 1610, 1611, 1612, and 1613 are similar to slot1450 and are distributed above and below a median 1640. The distancebetween each slot 1630 may vary from, for example, about ⅛ wavelength to1 wavelength. The length of a slot, such as slot 1612, may also varyfrom ⅛ wavelength to 1 wavelength. Additionally, the distance 1634between the end of a waveguide 1620 and an initial slot, such as slot1613, may vary, for example, between about ⅛ wavelength and 1 wavelengthand multiples thereof. In some aspects, distance 1634 is a quarterwavelength from the end of the waveguide 1620.

In some aspects single and/or doublet conducting rods, and/or multiplesthereof are placed in the slots of a slotted waveguide. FIG. 17 shows awaveguide 1700 comprising conducting rods 1710, 1711, 1712, 1713, 1714,1715, 1716, 1717. Conducting rods 1710 to 1717 may be placed a specifieddistance into waveguide 1700, as shown at 1720, 1721, 1722, 1723, 1724,1725, 1726, and 1727, respectively.

In some aspects, a doublet conducting rod may be placed in slots ofwaveguide 1500 and/or 1600. In some aspects comprising doubletconducting rods, the doublet conducting rods may be placed above orbelow line 1540 and/or 1640. For instance, if doublet conducting rodsare placed in slots 1611 and 1613 of waveguide 1600, then optionally noconducting rods may be placed in slots 1610 and 1632. Further, slots1610 and 1632 may be omitted from waveguide 1600 or may be coveredutilizing metallic tape so that no energy is delivered through slots1610 and 1632. In other aspects, single conducting rods may be placedboth above and below line 1540 and/or 1640 at the same time. In certainaspects, if slots above and below a line, such as line 1540, arepopulated with doublet conducting rods, then the microwave energyreflected back into waveguide 1600 rather than transmitted into thechamber becomes excessively high and the load receives less energy. Incertain aspects, a distance between each slot, such as distance 1630,may be between a half and a quarter wavelength.

A port may be tuned by varying the depth of a conducting rod in awaveguide, as shown in FIGS. 18A, 18B, and 18C. Each of FIGS. 18A-C showa slotted waveguide 1800 with conducting rod 1810. FIG. 18A shows aconducting rod placed into a slot at a depth 1820 less than a quarter ofa wavelength. FIG. 18B shows a conducting rod placed into a slot at adepth 1820 equal to a quarter of a wavelength. FIG. 18C shows aconducting rod placed into a slot at a depth 1820 greater than a quarterof a wavelength. Varying the depth of the conducting rods allows forenergy distribution within a chamber to be customized, as a depth lessthan a quarter of a wavelength is capacitive, a depth equal to a quarterof a wavelength is resistive, and a depth greater than a quarter of awavelength is inductive.

In some aspects, a port may be tuned by frequency band feasibility usingindividual slot and conducting rod configurations in order to maximizeenergy at multiple smaller frequency bands. In one aspect, an efficientband may be created using 6150 GHz+/−100 MHz. Because ports may be tunedby varying standing wave patterns within the waveguide, a controlalgorithm may be developed to average the energy delivered from all ofthe ports surrounding the load. A map of energy delivered by port byfrequency band (a portion of the total available variable frequencyband) as a function of tuning piston position can be leveraged to choosefavorable piston position, partial frequency band (of total availablevariable frequency band), power, and time power is delivered to enableparticular power distribution from all the ports. Many of theseparticular conditions may be programmed in series to createcontrollable, customizable energy distribution within the chambercontaining the load over the heating cycle. As a result, a more uniformtemperature may be obtained within the total volume of the irregularload.

In some aspects, energy distribution may be customized by switchingbetween single and double conducting rods at various frequencies.Switching between a single and double conducting rod allow for highefficient wave propagation into a chamber.

FIG. 19 shows slotted waveguides 1911 and 1912 that form a first chamber1910 with a second chamber 1913, where the first chamber 1910 formed bythe waveguides 1911 and 1912 is larger than the second chamber 1913.Chamber 1910 terminates on one end with a piston 1970, which may beadjusted to alter the energy distribution within chamber 1910. Slottedwaveguide 1911 has conducting rods 1942, 1943, 1944, 1945, 1946, 1947,1948, 1949, 1950, 1951, 1952, and 1953. Slotted waveguide 1912 hasconducting rods 1930, 1931, 1932, 1933, 1934, 1935, 1936, 1937, 1938,1939, 1940, and 1941. In some aspects, chamber 1913 has windows thatallow conducting rods 1930-1953 to be inserted into the chamber, asfurther described in FIG. 20. FIG. 20 shows a chamber 2000, similar tochamber 500. Chamber 2000 has windows 2010 and 2011 in side portions 506and 505, respectively. Slotted waveguide 2020 may be placed next to orin a window, such as window 2010. Slotted waveguide 2020 has slots 2030,2031, 2032, 2033, 2034, and 2035 which are similar to 1410 and 1450 andhave conducting rods 2040, 2041, 2042, 2043, 2044, 2045, 204, 2047,2048, 2049, 2050, and 2051. A window, such as window 2011, may be placedalong a top portion 502, bottom portion 504, or side portions 501, 503,505, and 506.

In additional aspects, dielectric materials with dielectric constantsranging from one to infinity may be placed within one wavelength of theports, waveguide and/or conducting rods. In one aspect, a dielectricconstant of materials of a chamber may be higher than the dielectricconstant for a conducting rod. Further, the dielectric constant for adielectric material comprising a cavity within a chamber may be higherthan the dielectric constant of materials of a chamber. Additionally,the dielectric constant of the load may be higher than the dielectricconstants for the conducting rod, the chamber and higher than or equalto the dielectric constant for the dielectric material comprising acavity. In one aspect, conducting rods and windows are surrounded byaluminum to carry currents into the second chamber.

A port may be tuned using a variable position shorting piston past thelast port. This changes the standing wave pattern within the waveguideand allows individual frequency wave fronts to couple with differentconducting rods. A change in the standing wave pattern may also beobtained by changing the waveguide distance before the first conductingrod and slot. Additional techniques, such as variable stub tuning and online tuning techniques using adjustable short positions within legs of amagic tee.

Features and subcombinations are of utility and may be employed withoutreference to other features and subcombinations of the slottedwaveguide. Additional applications of a slotted waveguide beyond theapplication to a shoe sole may be possible and obvious to one skilled inthe art.

Cage

A further example of a system in accordance with the present inventionmay be referred to as a cage. A cage may comprise a chamber formed fromwalls of a conducting material with openings permitting microwave energyto enter the interior of the chamber. Aspects of a cage facilitates acustomization of energy distribution to accommodate various loadcharacteristics using a plurality of openings where microwave energy ispicked up and transmitted into a chamber using plurality of openingsthrough the perimeter walls of the chamber.

A chamber may be similar to chamber 500 having 9 top panel 502, bottompanel 504, and side panels 501, 503, 505, and 506 made of conductingmaterial(s), at least in part. The top panel, bottom panel, and sidepanels, which may also be referred to as perimeter walls, may be formedof conducting materials. One or more of the panels may have a pluralityof openings that allow microwave energy to enter the interior volume ofthe chamber. FIGS. 21 a and 21 b show an exemplary top portion 2102 andbottom portion 2104 of a chamber with plurality of openings 2111, 2112,2113, 2114, 2115, 2116, 2117, 2118, and 2119 in top portion 502 andplurality of openings 2121, 2122, 2123, 2124, 2125, 2126, 2127, and 2128in bottom portion 504. A chamber may comprise a retention mechanism thatmay be engaged to secure the top panel 502, bottom panel 504, and sidepanels 501, 503, 505, and 506 to retain a dielectric, cavity and load ata predetermined pressure.

In the present examples, chambers are described using walls havingsufficient thickness to provide structural integrity for the overallsystem. In some examples, however, one or more dielectrics selected foruse may have sufficient rigidity to provide sufficient structuralintegrity for the system. In such an example, conducting walls (orpanels) may be very thin and/or may provide otherwise unattainablepatterns. For example, the panels in such an example may compriseconducting tape, a conducting film, an application of conductingnanoparticles, etc.

Distances 2130, 2131, 2132, 2133, 2134, 2135, 2136, 2137, 2138, 2139between the openings 2111-2119 located on top portion 2101 may vary fromone another, and may vary from distances 2121, 2122, 2123, 2124, 2125,2126, 2127, and 2128 between openings 2140-2148 located on bottomportion 2104, such that the openings of top portion 2102 and bottomportion 2104 may align with one another or be offset from one another.Additionally, as shown in FIG. 21C, a bottom portion 2104 may contain noopenings. FIG. 21D illustrates two openings of 2102 showing openings2119 and 2120. Opening 2119 has a height of 2154, a width of 2150 and alength of 2152. Opening 2120 has a height of 2160, a width of 2158, anda length of 2156. Each of 2154, 2150, 2152, 2158, 2160, 2156 may measurefrom about 1/32 to ¾ of a height, width, or length of a top portion2102. Additionally, each of 2154, 2150, 2152, 2158, 2160, 2156 maycomprise equal or different measurements from one another. Additionally,a opening may have a full length and/or a full width equal to a lengthand/or width of a portion of a chamber.

Additionally, FIGS. 21E-G illustrates various configurations of openingsthat may be comprised within portions of a chamber. FIG. 21E illustratesopenings 2199 at an diagonal angle in top portion 2102. FIG. 21Fillustrated openings 2199 in a crosshatch patter in top portion 2102.FIG. 21G illustrates a top portion 2102 comprising openings at variousorientations. For instance, openings 2190 are of a crosshatch design,openings 2191 are at a first angle and openings 2192 are at a secondangle.

FIGS. 22A and 22B illustrate aspects of the present invention concerninga variety of shapes of a dielectric material comprising a cavity. FIG.22 comprises a chamber 2210 housing a dielectric material 2220comprising a cavity 2230. Dielectric material 2220 may be fairly uniformin shape and may comprise dielectric material of the same dielectricconstant. FIG. 22B comprises a chamber 2210 housing dielectric material2240 forming a cavity 2230. Dielectric material 2240 is not uniform inshape. Dielectric material 2240 may comprise a first dielectric material2242 and a second dielectric material 2244. First dielectric material2242 may have a dielectric constant different from that of seconddielectric material 2244.

Utilizing the chamber, the assembled chamber may be placed in anapplicator chamber. The applicator chamber may be larger than theassembled chamber and large enough to maintain standing wave and/or maybe a continuous feed microwave oven. Microwave energy within theapplicator chamber may enter the chamber through openings of thechamber.

An opening within a chamber may be of a variety of shapes and sizes. Anopening may be oval, round, and rectangular. An opening may be 1/32 to ½a length of a top portion, bottom portion, or side portion of a chamber.Additionally, plurality of openings may be evenly or unevenly spaced1/32 to ½ a length of a top portion, bottom portion, or side portion ofa chamber. An opening may be oriented at angled zero to 180 degreesagainst an energy field.

A plurality of openings within a top panel may be aligned with aplurality of openings within a bottom panel. In some aspects, theplurality of openings in the top panel may be offset by a distance of 1wavelength or multiples thereof. The each of the plurality of openingsmay be parallel to one another or at various angles to one another. Anopening may have a first portion located at a first surface facing awayfrom an interior of the chamber and a second portion located at a secondsurface facing into an interior of the chamber. A width of the firstportion of the opening may be greater than, equal to, or less than awidth of the second portion of the opening. The first portion of theopening may be aligned with the second portion of the opening.Alternatively, the first portion of the opening may be offset from thesecond portion of the opening by a distance up to 1 wavelength.

Aspects of a chamber have dielectric material comprising a cavity thatmay retain a load. The dielectric material comprising a cavity may bemade of material with a dielectric constant ranging from one toinfinity. The cavity may be used to retain a load, such as a molded partand materials associated with a shoe sole.

In some aspects, an opening may be partially or entirely filled withdielectric material in order to make the opening electrically larger andallow more energy to enter the interior of the chamber via the opening.As described above, microwave energy moves from a low dielectric to ahigh dielectric constant material. By adding dielectric material to anopening, energy may be configured to move into the opening and into thechamber in a desired fashion. Multiple types of dielectric materialswith different dielectric constants may be placed in a single opening.For instance, a dielectric constant of a portion of material near theoutside of an opening may be less than a dielectric constant of aportion of material near the inside of an opening.

In some aspects a cage may be well suited for curing a load within anapplicator chamber having a standing wave pattern. In some aspects, acage may be placed within a nearfield of an applicator chamber. In otheraspects energy may be introduced within the applicator chamber and thechamber at different polarizations. Additionally, in some aspectsconducting rods may be added to openings of a chamber in order toeffectively force energy into the chamber. An introduction of conductingrods into openings of a chamber may comprise features similar to thefeatures and aspects described in relation to the slotted waveguide.

Process for Affixing EVA to Rubber

Utilizing aspects of the present invention discussed above, an EVA itemmay be affixed to a rubber item. As will be described further below, atleast one advantage of utilizing aspects of the present invention toaffix an EVA item to a rubber item may be that, in some aspects,adhesives and primers are not necessary to affix the EVA item to therubber item. However, in other aspects, adhesives and primers may beused to facilitate affixing the EVA item to the rubber item.

In an exemplary process of affixing an EVA item to a rubber item, aswill be discussed in detail below, a rubber item and an EVA item may beeach prepared utilizing aspects of the present invention or usingconventional methods. The prepared EVA item may placed in contact with,for example on top of, the prepared rubber item within a cavity formedin at least a first dielectric material. The dielectric material havingthe cavity, the prepared EVA item, and the prepared rubber item may beplaced within a chamber. Pressure may be applied to the EVA item and therubber item to bring them into intimate contact. Microwaves may beapplied to the chamber causing the EVA item and the rubber item whilepressure is applied. For illustration purposes, FIG. 23 illustrates atop portion 2315 of a dielectric material with a top portion 2315 ofcavity extending therein, a bottom portion 2345 of a dielectric materialwith a bottom portion 2345 of the cavity extending therein, with an EVAmaterial 2320 and a rubber material 2330.

The cavity and the dielectric material containing the cavity used inbonding the rubber item and the EVA item may be similar to the cavityand dielectric materials described above in aspects related to theexamples of the multiport launch, slotted waveguide, and/or cageexamples. The dielectric material containing the cavity may be comprisedof material similar to LSR, PTFE, and/or epoxy described above. Thedielectric material may have a dielectric constant less than or equal tothe rubber item and/or EVA item allowing heat to be transferred to therubber item and EVA item effectively. The chamber may be configured tobe able to withstand microwaves and temperatures up to 200 degreesCelsius.

The prepared EVA item may be placed onto the prepared rubber item. Theprepared EVA item may be a foamed EVA or a solid EVA. The preparedrubber item may be less than fully cured, i.e. uncured or partiallycured. Both the prepared rubber item and prepared EVA item may be housedwithin a cavity in the dielectric materials. The dielectric materialsmay have dielectric constants less than or equal to dielectric constantsof the prepared rubber item and the prepared EVA item, although thisneed not be the case in all uses of systems and methods in accordancewith the present invention. The dielectric material with the cavityhousing both the prepared rubber item and prepared EVA item may beplaced within a chamber. Optionally, the prepared EVA item, preparedrubber item, dielectric material, and/or chamber may be preheated. Thechamber may have features similar to aspects of the invention describedabove in the examples of the multiport launch, slotted waveguide, and/orcage examples. Microwave energy and pressure may be applied to thecavity, prepared rubber item and prepared EVA item for a specifiedamount of time, causing the rubber item to bond to the EVA item.Additionally, in some aspects, a pressure component, such as a clamp,may be applied to the prepared EVA item and prepared rubber item suchthat pressure is applied to press the prepared EVA item and preparedrubber item into one another before, during, and/or after the heatingprocess. Utilizing aspects of the present invention may allow a rubberitem to bond to an EVA item without using primers or adhesives.

FIG. 25 illustrates a method of bonding an EVA item to a rubber item. Atstep 2510, an EVA item may be prepared, either using conventionalmethods or methods described herein. At step 2520, a rubber item may beprepared using conventional methods or methods described herein. Therubber item prepared in step 2520 may be less than fully cured. In step2530, the prepared EVA item may be placed in contact with, for exampleon top of, the prepared rubber item. In step 2540, microwave energy andpressure may be applied to the EVA item and the rubber item to bond themtogether.

From the foregoing, it will be seen that this invention is one welladapted to attain all the ends and objects hereinabove set forthtogether with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

Since many possible aspects may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

Having thus described the invention, what is claimed is:
 1. A system foraffixing an Ethylene-vinyl acetate item to a rubber item, the systemcomprising: a chamber, the chamber comprising a first dielectricmaterial with a cavity, the cavity configured to receive theEthylene-vinyl acetate item and the rubber item in a layered fashion achamber cover removably coupled to the chamber, the chamber cover havingan aperture extending through the chamber cover, the aperture fullycontaining a second dielectric material, the first dielectric materialand the second dielectric material having greater loss properties thanthe chamber cover when exposed to microwave energy; a pressure sourcethat applies pressure to the second dielectric material in anorientation that compresses the Ethylene-vinyl acetate item and therubber item together; and at least one source of microwave energy thatapplies microwave energy to both the Ethylene-vinyl acetate item and therubber item through the second dielectric material.
 2. The system foraffixing an Ethylene-vinyl acetate item to a rubber item of claim 1,wherein the chamber comprises an interior and an exterior, the interiorof the chamber at least partially filled by the first dielectricmaterial.
 3. The system for affixing an Ethylene-vinyl acetate item to arubber item of claim 2, wherein the chamber is formed from a pluralityof conductive walls.
 4. The system for affixing an Ethylene-vinylacetate item to a rubber item of claim 2, wherein the at least onesource of microwave energy comprises a port permitting microwave energyto pass from the exterior of the chamber to the interior of the chamber.5. The system for affixing an Ethylene-vinyl acetate item to a rubberitem of claim 1, the system further comprising: an Ethylene-vinylacetate curing device that applies heat and pressure to at leastpartially cure the Ethylene-vinyl acetate item before the Ethylene-vinylacetate item is received in the cavity.
 6. The system for affixing anEthylene-vinyl acetate item to a rubber item of claim 1, the systemfurther comprising: a rubber curing device that applies heat to at leastpartially cure the rubber item before the rubber item is received in thecavity.
 7. The system for affixing an Ethylene-vinyl acetate item to arubber item of claim 1, wherein the cavity is within the firstdielectric material.
 8. The system for affixing an Ethylene-vinylacetate item to a rubber item of claim 1, wherein the second dielectricmaterial is polytetrafluoroethylene.
 9. The system for affixing anEthylene-vinyl acetate item to a rubber item of claim 1, wherein theaperture within the cover is substantially square, rectangular, orcircular.
 10. The system for affixing an Ethylene-vinyl acetate item toa rubber item of claim 1, wherein the aperture within the cover is anarray of apertures.